Fork lift truck structure



Aug. 13, 1968 L- J. FISCHER 3,

FORK LIFT TRUCK STRUCTURE Filed July 5, 1966 INVENTOR. Lsounnn J. fiscusn z/wm/Mmww/ w v ll/051508 United States Patent 3,396,862 FORK LIFT TRUCK STRUCTURE Leonard J. Fischer, RR. 5, Shelbyville, Ind. 46176 Filed July 5, 1966, Ser. No. 562,582 3 Claims. (Cl. 214-620) ABSTRACT OF THE DISCLOSURE An overhang boom attachment having a pair of spaced horizontal tubes adapted to fit over the prongs of a fork lift truck, the tubes having their distal ends joined together by a cross member, the tubes and cross member cooperatively supporting a boom having a depending hook.

The present invention relates to an attachment for increasing the utility of fork lift truck-s.

Fork lift trucks are extensively used in plant yards, warehouses and the like for picking up and shifting heavy boxes, crated goods and other heavy objects from one point to another. The trucks have an upstanding elevator frame which includes transversely spaced side members. Supported between said members for up and down movement in a conventional manner is a carriage, which is controlled by a suitable power means. In order to lift an object, the transversely spaced side members must be engaged under the object. This frequently slows down moving operations. The fork lift trucks are also limited in their utility, as the width of the goods must be less than corridors and doors through which they are to be moved. Loading and unloading heavy objects from an enclosed area such as a truck bed is also a problem with conventional fork lift trucks.

In order to overcome the above disadvantages, various hoist units have been suggested and disclosed in the prior art. However, they are complicated and expensive.

Therefore, it is a primary object of the present invention to increase the efiiciency and utility of fork lift trucks by providing a simple, inexpensive boom attachment to overhang the goods and which is readily mounted on the elevator carriage of the truck for movement therewith so that no block and tackle for the boom hook is necessary.

A further object of the present invention is to provide a boom for a fork lift truck having means for detachable but rigid connection with the elevator carriage so that the truck is usable with or without the boom.

It is a further object of the present invention to provide a boom attachment for a fork lift truck which requires no alteration of the truck in order to be usable therewith. I

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIGURE 1 is a perspective view of one embodiment of the boom attachment;

FIGURE 2 is a bottom view of the boom attachment;

FIGURE 3 is a side view of the boom attachment coupled to a lift truck and illustrating the mobility thereof; and

FIGURE 4 is a side view of the boom attachment coupled to a lift truck illustrating the unlimited mobility thereof. a

One embodiment of the present invention might include an overhang boom attachment usable with a fork lift truck having an upstanding elevator frame including transversely spaced side members for engaging and lifting an object to be moved. The boom comprises a pair of spaced, horizontal tubes adapted to fit over the length of the transversely spaced side members so that the proximal ends of the tubes are adjacent the elevator frame. The distal ends of the tubes are joined together with a piece of hot rolled steel which reaches across both the distal ends. Several spacer bars are joined to the undersides of the tubes.

Immediately behind the piece of hot rolled steel is a third piece of tubing of the same size as the spaced horizontal tubes which serves to strengthen the distal end structure. A fourth section of tubing extends diagonally upwardly and outwardly from the tubing-hot rolled steel end structure. The distal end of the upwardly extended tubing is cut so that a horizontal section of tubing may be welded thereto to form a boom structure.

A downwardly depending hook is associated with the distal end of the horizontal tubing section. A second downwardly depending hook is associated with the steel platediagonal tube junction, and a plurality of smaller hooks are associated with the sides of the horizontal tube member of the boom structure. Bracing means are provided for the boom structure at several points as will be hereinafter described in detail.

Referring more particularly to the drawings, the boom or hoist unit attachment 10 can be readily constructed by spacing a pair of horizontal tubular members 11 so that the distance between the tubular members 11 corresponds to the distance between the transversely spaced prongs 12 of a fork lift truck 13. A first steel spacer plate 14 is welded to the underside of the tubular members 11 adjacent the end to be coupled to the prongs 12 and a second identical plate 14 is coupled to the underside of the tubular members adjacent the opposite end thereof. The opposite end will be referred to as the distal end of the unit.

A piece of hot rolled steel 15, which reaches across the distal end of both tubular members 11, provides a means for supporting a first boom arm 16, which extends outwardly and upwardly from the distal end of the unit to form a diagonal arm portion of the boom 17. The proximal end of arm 16 is welded to an additional support member 18 which abuts the steel spacer plate 14' flat braces 23-.

A large downwardly depending hook 24 is pivotally supported adjacent the distal end of arm 19 by a pair of bracket plates 25. A second large downwardly depending hook 26 is coupled to the underside of arm 16 adjacent the steel plate 15. A pair of smaller hooks 27 are coupled to the sides of arm 19.

Of course, the illustrated embodiment utilizes cylindrical tubing for the arm portion; however, the scope of the invention is not limited to such.

It is to be noted that no bolts are necessary to attach the hoist attachment 10 to a fork lift truck. As can be seen in FIGS. 3 and 4, the horizontal tubular members 11 are merely slipped over the spaced prongs 12 of the fork lift truck 13. The prongs and tubular members are of sufficient length that there is no danger of accidental disengagement. Further, only downward pressure is exerted on the unit and hence the unit remains securely on the prongs. Hoist attachments within the scope of the present invention may be adapted to be usable with fork lift trucks of varying sizes and having varying distances between their transversely spaced prongs.

FIGURE 3 is illustrative of one of the crane operations which affords unlimited mobility for a fork lift truck 13. In this instance, a bulky, heavy object 30 can be loaded to the center of a truck 31 having either a load or walls on either side. The truck has greater mobility than a large crane, and such an attachment has many practical applications.

FIGURE 4 illustrates yet another application of the present invention. Where lumber, tubing or other long objects illustrated by reference numeral 33 must be moved, the attachment of the present invention permits a fork lift truck to be utilized.

The attachment, operation and disengagement of the hoist attachment of the present invention is so simple for the operator that efficiency is greatly increased, as is the utility of the fork lift truck. Thus, the advantages of a crane have been simply but effectively combined with the mobility of a fork lift truck.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, references being had to the appended claims.

The invention claimed is:

1. In a fork lift truck including a wheel supported body, an elevator frame upstanding from the body, and a carriage movable up and down said frame, said carriage including a pair of vertically spaced transverse prongs extending outwardly therefrom; a hoist attachment adapted to interfit over said prongs and be carried thereby, said hoist attachment comprising: a frame and a boom, said frame including a pair of parallel tubular members adapted to slide over the spaced transverse prongs of said carriage and to be carried thereby; said boom extending upwardly and outwardly from said frame; said tubular members being substantially the same length as the transverse prongs of said carriage, so as to be supported entirely by said prongs, said hoist attachment thereby being readily attached to and removed from said carriage; said tubular members having an inner diameter such that said member fits snugly over said transverse prongs; a first spacer bar welded to the underside of said tubular members adjacent the proximal end of said frame; a second spacer bar welded to the underside of said tubular members 'adjacent the distal end of said frame; a bar of hot rolled steel welded to the distal ends of said tubular members, thereby forming an elongated U-shaped frame; means for reinforcing said distal end structure adjacent said steel bar; said steel bar having a cut out portion for receiving and supporting said boom.

2. In a fork lift truck in accordance with claim 1, said boom including a first arm extending upwardly and outwardly from the distal end of said frame; a second arm coupled to said first arm, said second arm being parallel to the floor; a first downwardly depending hook pivotally coupled adjacent the free end of said second arm, a second downwardly depending hook fixedly coupled to said first arm adjacent the distal end of said frame.

3. In a fork lift truck in accordance with claim 2, said hoist attachment additionally comprising means for bracing said boom to said frame and means for bracing the joint between said first and second boom arms.

References Cited UNITED STATES PATENTS 2,364,493 12/ 1944 Ulinski 214-620 2,575,552 11/1951 Glenn 2l4-620 3,007,592 11/1961 Adams 214-620 ROBERT G. SHERIDAN, Primary Examiner.

R. BALLANTYNE, Assistant Examiner. 

